Are littlebee 20A ESC's enough for RS2205 red bottoms motors?

Short answer is yes.
But I would personally go for the Littlebee 30A or the DYS XM20A ESC's, because of the better F396 MCU. Oscar has a write up about why:
https://oscarliang.com/xm20a-esc-f396-review/

have a look at the manufacturer spec sheet of the motor you want to buy and see what amps get pulled at 100% throttle.

for example the Emax red bottom RS2205 will pull nearly 30amps on a 5045 prop on 4S. the littlebee PRO or the DYS xm30's are the ESC of choice as the processor on them is over 2x faster than other ESC's and can keep up with these new generation of 2205 and high KV motors better.

I'd say it depends on what KV motor are You planning to run. Littlebees should handle 2300kv even on 2khz motor update rate (4khz FC looptime). You may have to lower looptime on 2600kv one though.

But this is just theory from what I've read, not tested personally.

As it comes to amp rating - remember that motors in air tend to draw about 30% less current than on the bench. Also - You're not always at 100% thrrottle.